intermittent heating element outage

Hi - we recently installed a Marey GA16LP propane unit for an outdoor shower. We have it installed with an inline filter. It was working beautifully for several weeks, using water from a 1550-gallon cistern that was filled with chlorinated municipal water. This week we finally got our well in and routed the water to the outdoor shower. It was working fine until today, when the heating element began to intermittently shut off. All propane connections look good. Logic says it has something to do with the well water, but we assumed the good inline filter would take care of any residue. Anyone have a problem like this, or know of anything else we should be checking?

I would check to see what the system says the water flow is first. Then make sure it meets the manufacturer's specs. Other issues could be gas pressure. I have never worked on a Marey before but most newer models rely on a balanced gas pressure for proper air/ gas mixture, if the gas pressure fluctuates too much the burner could cut out due to a poor flame signal.
Also make sure the intake air filter is not plugged up if there is one...